NWARG : Making a patch cable connector

Turning a RJ45 Inline coupler into a patch cable connector

Why

There are many situations that you you would want a two computer network. My particular one was when I wanted to connect to my brother's computer in his bedroom while we were both home for Christmas. I have a small 10BaseT hub, but it's faster using a straight through connection and the way I've had it strung up the cable in the hall it would difficult using the hub. We also wanted to share a dial up connection as was similar to the way some of the guys at college had at the time.

It's also handy to have the ablity to direct connect at lanparties you can temporarily disconnect yours and someone else's computer to transfer massive files quickly. Usually you have stuff that you want to get and forget until everyone starts to leave, shutting off DCHP servers and hubs. An advantage of this is that you can connect at the highest speed that both computers can communicate. These days, thats a 1GB connection. While 100MB switches are common at lanparties, 1G networks are not.

You can hookup two computers in a two computer local area network (also referred as peer to peer, peer networking, direct connection, or sometimes as head to head when specifically regarding gaming purposes) with what is called a patch cable. I have a few long cables I purchased for use in local Lanparties but these are normal straight through cables. Patch Cables are mainly used for connecting two hubs together but now many hubs have an uplink port with the wiring designed to use the normal cables, so now they are typically harder to find in lengths over 10 feet (as most businesses that would use them have them made in-house) and are more expensive. Although I should note that you can use an unmodified inline coupler and a small patch cable if you decide to go that route. This would take a your length of normal cable + the inline coupler ($3) + a length of patch cable (~$10 for 9 foot).

Building

I bought a Belkin brand RJ45 Straight through Coupler at Office Depo in Fort Smith, Arkansas for around $2. I have a chart below that shows in detail why and what wires are changed, but what it boils down to is switching the Red for Orange and Green for Blue wires on ONE side of the connector. (The Belkin brand does not use standard wiring conventions that the cables do.) In a standard cable it would be Orange stripe for Green stripe and Orange for Green – much easier to remember! A small standard screwdriver will separate the plastic halves of the connector and can be used to depress the wire harness retaining clip to pull it out. One you have it open, remove the wires in pairs and pull out the back of the harness then switch. Use a pair of needle nose pliers to bend the end of the wire back to it's original shape. After you are done with both pairs, slide it into the plug / wire separator. Visually inspect and make sure they went in properly, and make sure only one wire is in each slot. Put the halves of the case back together and you have yourself an IPC. It should not require testing to make sure the wires conduct because the wires are fairly rugged, although I wouldn't handle them anymore than neccessary. You might want to use a marker an label it patch, because someone might come across it someday and try to use it as an inline connector.

The table below is oriented as if the cable's plastic retaining tab is oriented upwards looking into the inline coupler. If you have a nonstandard wiring in whatever brand of coupler you buy, you may have to use it to figure out what wires need reversing. Please do not contact me asking how to set up networking, as there are plenty of places you can go on the net for those resources. Most of the information used to make the coupler was gotten from the All Star Computers Peer Networking Help Page and Home PC Networking.

Internet connection sharing

If you want to share a dial up connection and use both computers at once the computer directly using an internet connection must be set up as a proxy server (an be on) for the other computer to use it. Windows OSs after 98SE have Internet connection sharing available as part of the operating system. However, I would recommend Jana Server. There are dedicated hardware solutions that hook up via ethernet to client computers, and will dial out on demand by modem serving multiple computers, but these are typically more expensive point of sale devices rather than consumer products. For cable / dsl connections it is better to use a router as a dedicated hardware solution rather that running an additional computer.

I hope this helps someone. I bought a hub because I didn't know you could setup a peer connection without one, although that hub has come in handy many times at lanparties.

Wiring Comparison between Normal and Patch Cables

Standard Inline	Brown	Brown Stripe	Orange	Blue Stripe	Blue	Orange Stripe	Green	Green Stripe
Belkin Straight Thru	White	Brown	Red	Black	Yellow	Green	Orange	Blue
Standard Patch Differences			Green			Green Stripe	Orange	Orange Stripe
Belkin Patch Differences			Orange			Blue	Red	Green

Last Modified: April 28th, 2008